Option to show current month income/expense with cumulative balance

[emavgl]

Description:
User wants the balance of the previous month to roll over to the new month, while income and expense amounts should be specific to the current month.

Requested behavior:

• Income and expense: show current month only
• Balance: show all records data (cumulative)

Current limitation:
At the moment there is no option to combine these two. There's a setting that allows showing income/expense and balance for all records, but not a mixed view.

Version: com.github.emavgl.piggybankpro-1.4.2